This fix is for 5.1 only : back porting the 6.0 patch manually

The parser code in sql/sql_yacc.yy needs to be more robust to out of
memory conditions, so that when parsing a query fails due to OOM,
the thread gracefully returns an error.

Before this fix, a new/alloc returning NULL could:
- cause a crash, if dereferencing the NULL pointer,
- produce a corrupted parsed tree, containing NULL nodes,
- alter the semantic of a query, by silently dropping token values or nodes

With this fix:
- C++ constructors are *not* executed with a NULL "this" pointer
when operator new fails.
This is achieved by declaring "operator new" with a "throw ()" clause,
so that a failed new gracefully returns NULL on OOM conditions.

- calls to new/alloc are tested for a NULL result,

- The thread diagnostic area is set to an error status when OOM occurs.
This ensures that a request failing in the server properly returns an
ER_OUT_OF_RESOURCES error to the client.

- OOM conditions cause the parser to stop immediately (MYSQL_YYABORT).
This prevents causing further crashes when using a partially built parsed
tree in further rules in the parser.

No test scripts are provided, since automating OOM failures is not
instrumented in the server.
Tested under the debugger, to verify that an error in alloc_root cause the
thread to returns gracefully all the way to the client application, with
an ER_OUT_OF_RESOURCES error.

Note: NULL merge of sql/sql_yacc.yy, the fix for bug#38296 will be provided separately for 5.1

Fixed missing DBUG_RETURN in the function find_key_block

This fix is for 5.0 only : back porting the 6.0 patch manually

The parser code in sql/sql_yacc.yy needs to be more robust to out of
memory conditions, so that when parsing a query fails due to OOM,
the thread gracefully returns an error.

Before this fix, a new/alloc returning NULL could:
- cause a crash, if dereferencing the NULL pointer,
- produce a corrupted parsed tree, containing NULL nodes,
- alter the semantic of a query, by silently dropping token values or nodes

With this fix:
- C++ constructors are *not* executed with a NULL "this" pointer
when operator new fails.
This is achieved by declaring "operator new" with a "throw ()" clause,
so that a failed new gracefully returns NULL on OOM conditions.

- calls to new/alloc are tested for a NULL result,

- The thread diagnostic area is set to an error status when OOM occurs.
This ensures that a request failing in the server properly returns an
ER_OUT_OF_RESOURCES error to the client.

- OOM conditions cause the parser to stop immediately (MYSQL_YYABORT).
This prevents causing further crashes when using a partially built parsed
tree in further rules in the parser.

No test scripts are provided, since automating OOM failures is not
instrumented in the server.
Tested under the debugger, to verify that an error in alloc_root cause the
thread to returns gracefully all the way to the client application, with
an ER_OUT_OF_RESOURCES error.

            
Server side cursors were not initialized properly and this caused a reference to
uninitialized memory.

	running on Windows

We used two OS-specific methods of looking up the executable 
name, which don't work outside of those two kinds of OSes 
(Linux+Solaris and Windows).

We assume that if the user ran this program with a certain 
name, we can run the other sibling programs with a similar name.

(re-patch in bzr)

Post-merge fix: remove spurious semicolon that caused the function
to return failure regardless of the outcome.

Fall back to "find" if bzr is unavailable.

Don't fail for paths that have spaces in them.

bk sfiles -> bzr ls

Post-merge fix: Alter linking order so that the thread linking
flags appear last in the list. This needs to be done this way
because some linkers will not search the thread archive again
if a undefined symbol (pthread_kill in this case) appears later.

      
Reset session sql_mode before creating system tables as it
is done in the mysql_fix_privilege_tables.sql script.

      
min() and max() functions are implemented in MySQL as macros.
This means that max(a,b) is expanded to: ((a) > (b) ? (a) : (b))
Note how 'a' is quoted two times.
Now imagine 'a' is a recursive function call that's several 10s of levels deep.
And the recursive function does max() with a function arg as well to dive into
recursion.
This means that simple function call can take most of the clock time.
Identified and fixed several such calls to max()/min() : including the IF() 
sql function implementation.

      
Community contribution fix for Serbian translation in error message list.

Fixed typo and removed duplicate call to get_current_user.

config/ac-macros/character_sets.m4 didn't mention hungarian collations
in the UTF8 and UCS2 lists.

Calling List<Cached_item>::delete_elements for the same list twice
caused a crash of the server in the function JOIN::cleaunup.
Ensured that delete_elements() in JOIN::cleanup would be called only once.

Removing duplicate 'setup' portions of these include files.  Likely an editor error created dupe lines.
This is causing many Pushbuild errors

     
Tables in the table definition cache are keeping a cache buffer for blob
fields which can consume a lot of memory.
    
This patch introduces a maximum size threshold for these buffers.